Markedly elevated high-sensitivity troponin and in-hospital mortality after cardiac surgery.

Background: High-sensitivity troponin (hsTnI) is correlated with cardiac mortality; however, studies on the relationship of markedly elevated hsTnI with in-hospital mortality after cardiac surgery are sparse. Therefore, we aimed to define this relationship in order to help guide in-hospital, acute management of post-surgical patients.

Methods: We retrospectively analyzed all cardiac surgeries completed at our institution between January 2020 and June 2022 in which a peak hsTnI was noted to be >35× upper limit of normal (ULN = 34 ng/L). The primary outcome was in-hospital death. Subgroup analysis was performed to assess differences between coronary artery bypass grafting (CABG) and other cardiac surgeries.

Results: A total of 1382 cases met inclusion criteria. The patients' mean age was 64.8 years and 68.2 % were male. Median peak hsTnI after surgery was 4202 ng/L (interquartile ratio: 2427-7654). Univariate analysis of troponin level with mortality found that for every 1000 ng/L increase in hsTnI, odds of in-hospital death increased by 3.8 % (odds ratio [OR]: 1.038; 95 % confidence interval [CI] 1.027-1.050; p < 0.0001). In a multivariate model, troponin (OR 1.02; 95 % CI 1.01-1.04; p = 0.004) maintained a significant association with in-hospital death. CABG was associated with a lower risk of in-hospital death for any given hsTnI level up to 60,000 ng/L compared to other cardiac surgeries.

Conclusion: Increasing hsTnI level is associated with increasing probability of in-hospital mortality and, therefore, serves as an additional, objective measure of risk to help guide in-hospital clinical management.